Shopping malls can do a better job of protecting shoppers from shooters, and it doesn’t take metal detectors, full-body searches, bomb dogs, legions of security officers or a lot of money, he says — it just takes the will.

Murphy helped implement a security plan at Bloomington’s Mall of America, one of the nation’s largest shopping malls. The framework for the plan grew out of a disaster averted nearly a decade ago.

In 2004, Murphy, then a patrol officer on the town’s east side, said he was sent to investigate a man who was giving polished stones and coins to children on a school playground. When Murphy located the man a block away, he found the man’s van stocked with rifles and “bags of ammunition.” The man said he had been “sent to Earth by Osama bin Laden,” Murphy said.

No one was harmed, but that wasn’t because of a quick, coordinated response by school and police officials. In fact, the response was a “calamity of errors,” Murphy recalls.

Angry, Murphy confronted the school principal, faulting her for not responding adequately to the threat. The principal, flummoxed, asked Murphy what she should have done, Murphy said.

And that’s when it struck Murphy: He had no idea.

“As a policeman, you’re used to having all the answers … and I didn’t have an answer,” Murphy said.

Murphy set out on “a quest.” He started looking for effective ways to respond to dangerous situations, including “active shooter” situations.

Murphy learned that at the time, Minnesota law required schools to have nine fire drills a year, even though no student had been killed in a school fire for some 40 years. But there was no comparable drill to protect students from deranged gunmen, dangerous non-custodial parents, terrorists, or other modern-day threats.

So Murphy became an advocate of “lock-down” drills — drills in which students and teachers barricade themselves from threats, a tactic that could protect them for the eight minutes it takes, on average, for police to respond.

Lock-down drills became Murphy’s obsession. Building on the work of others, he pushed for all schools to have lock-down drills. In 2006, Minnesota became the first state to require lock-down drills in all schools.

The legislature mandated five lock-down drills and five fire drills a year.

Then, in 2007 and 2008, a spate of shootings struck American shopping malls. “And I started to go, ‘Wait a minute. What’s working in our schools can work in our shopping malls too,” Murphy said.

With his department’s encouragement, Murphy said he approached the Mall of America’s management with the idea of lock-down drills. They bit.

So now, twice a month — once in the morning and once in the evening, assuring that both work shifts become acquainted with the drills — the mall’s security department asks patrons to seek shelter in the nearest mall store. An alarm buzzes, and a “lock-down” message is delivered electronically to every store. The store gates are lowered, lights are turned off, and shoppers huddle in a safe spot, typically the back room. The drills last only a few minutes.

“The whole goal of a lockdown is to minimize potential victims while maximizing the time in which the police can get there to solve your problem,” Murphy said.

This exercise costs virtually nothing. Any shopping mall, office building, or establishment with a public address system can conduct one. It does not infringe on anyone’s constitutional rights. Participation is voluntary; any shopper who does not want to participate can simply walk away. Few do.

The Mall of America thinks the program is of such value that it mandates participation in store leases, Murphy said.

“When a new store manager says, do I have to do this, the answer is yes,” Murphy said. “It takes time and commitment and the willingness to work through it and see it to fruition,” he added. “And you also have to actually practice your plan. It’s got to be a living plan, and you practice it often.”

Need a plan? Steal Murphy’s.

“I encourage plagiarizing,” he said. (You gotta love a cop who encourages you to steal.)

Lock-down drills are “not a silver bullet,” Murphy acknowledges. “Sad to say, there is no silver bullet. If the bad buy gets in your space, it’s time to attack or flee,” he said.

But, Murphy says, if the Mall of America can do it, with its 500 stores, huge eatery, and indoor amusement park, your shopping mall can do it too.

And they will, he says, if they care more about protecting people than merchandise.